Operating PrincipleThe operational principle of hydraulic ram is very simple. It uses the water hammer. effect in the ram to transmit water from lower elevation to a much higher elevation.. Ram pump has only two moving parts that dictates the whole operation. These are the waste valve or the impulse valve and the check valve. Of course there are are other parts that supports channelling of water.

In orrder to operate, you must have a source of water situated above the pump. For example, you must have a spring source at least 1 meter above the Ram so that the water from the spring could flow and build up momentum towards the ram. . The spring box and the ram is connected by a pipe called drive pipe.. * Once the water reaches its maximum speed, this waste valve (impulse valve) slams shut, thus creating a water hammer effect.
* As it slams shut, the flowing water develops a great deal of pressure in the pump because of its inertia.
* The pressure forces open a second valve, the check valve.
* High-pressure water flows through the second valve (check valve) to the delivery pipe (which usually has an air tank to allow the delivery pipe to capture as much high-pressure water as possible during the impulse).
* The pressure in the pump falls. The first valve re-opens to allow water to flow and build up momentum again. The second valve closes.
* The cycle repeats

The volumetric efficiency of the ram depends on the FLOW of water from the source; the FALL or the height of the water source from the ram and the LIFT or the difference in height between the ram and the reservoir.

DisadvantagesThe disadvantage of ram is that, through the waste valve, it throws back to ground considerable amount of water since not all water that enters the ram are pumped uphill as compared to electrically or petrol driven pumps where it has no waste water...

Advantages- It uses no electricty nor fuel, thereby, saving you on high cost of energy.- Minimal maintenance as it has only two moving parts, therefore, reducing the "wear and tear" of the machine.- Easy to operate- 7/24 operation. It operates seven days a week; 24 hours a day.___________________________Reference:http://science.howstuffworks.com/question318.htm

Helpful link:http://www.i4at.org/lib2/hydrpump.htm

How Ram Pump Works?

History of Ram Pump*In 1772, John Whitehurst developed the first known machine to utilize the water hammer effect to pump water. He used a hand-operated Impulse valve, employing child labor to open and close the valve in continuous cycles.

In 1776, Joseph Michael de Montgolfier invented a similar machine but replaced the hand operated valve with an automatic impulse valve which was opened and closed by the rebound wave inside the hydraulic ram itself. Montgolfier's machine was called " Le Bel'ier Hydraulique", from which the term "hydraulic ram" was derived. The invention was so simple and reliable. It has survived over 200 years with very little change._________________________*Taken from Ram Pump manual published by Peace Corps